1. Field of the Invention
The present invention concerns the field of equipment for video teleconferencing and, more specifically, an improved design for a terminal that allows eye contact between a local conferee and a remote conferee at a second terminal.
2. Description of Related Art
The use of partially silvered mirrors is well documented in the art for producing eye contact while desktop videoconferencing. Either the mirror reflects the display similar to a teleprompter with the camera behind the mirror or the mirror reflects the image of the conferee viewing the display through the mirror of which that reflection is captured by a camera. This later arrangement has been utilized in behavioral research studies in the form of closed circuit videoconferencing for more than twenty-five years. Prior art FIG. 1 illustrates such a common arrangement that has been used to enable eye contact between research participants where each participant has a similar terminal so both can enjoy an eye contact image of the other. Here the conferee peers through a partially silvered mirror 6 to a display screen 8 of a display 2. A camera 4 captures an image of the conferee from the reflection of a mirror 10 and the partially silvered mirror 6 of which the captured motion images are transmitted to a distant terminal. A contrast shield 14 and a reflection shield 12 ensures unwanted ambient light does not strike the partially silvered mirror 6. This optical configuration when retrofitted to an existing display adds considerable bulk and prevents direct access to the display screen. A housing (not shown) usually includes all the eye contact components fixed so that they do not lose alignment. Numerous methods over the years have been utilized to attach the housing to the display and even repositioning the housing above the display 2.
Rather than removing the optics from the front of the display screen 8 prior art FIG. 2 illustrates the disclosure of the use of image blocking film as seen FIG. 17 in U.S. Pat. No. 5,777,665 in which the protrusion of the partially silvered mirror 6 is angled at around 30 degrees instead of the usual 45 degrees. The image blocking film 16 permits the camera 4 to be aimed directly toward the display screen without light from the display affecting the reflectivity of the partially silvered mirror 6. The contrast shield 14 ensures ambient light does not reduce the reflectivity of the partially silvered mirror 6. The reflection shield 12 ensures the desk and keyboard are not reflected over the display screen 8 and thereby disrupting the quality of the image. While this approach works substantially as designed, the protrusion of the beamsplitter 6 still awkwardly interferes with the normal use of the display screen 8, especially for touch screen applications.
A retractable devise has been proposed as illustrated in prior art FIG. 3 which is documented in U.S. Pat. No. 5,666,153 to Copeland attempts to reposition the partially silvered mirror 6 by removing it from the front of the display screen 8 and storing it above the display 2. The device, as illustrated and described, is designed for the depth of a CRT monitor of which the partially silvered mirror 6 tilts upward with less than 1/4 of a revolution by a hinge 26 upon a retracting camera hood 18. Opposite the camera 4 on the other side of the partially silvered mirror is the contrast shield 14 which assures ambient light does not interfere with the reflectivity of the partially silvered mirror 6. The retracting camera hood 18 retracts with a sliding motion upon a track 20 so that the entire optics from the front of the display screen 8 lay on top of the display 2. The track 20 is clamped in place by pressure clamps 22 and 24. The drawbacks to this "mounted" device, however, are numerous. The track device is a cumbersome element which even when retracted still appears bulky and awkward-looking which is a distraction in an office setting. Still further, the retracting slide mechanism itself adds expense to the construction of the device and does not readily clamp upon the new organic monitor housing designs enjoyed by millions of consumers. Lastly, and most significantly, the retracting slide mechanism is not transferable to flat panel displays. In fact, if adapted with significant modifications to flat panel displays, the flat panel display will no longer be flat but be 14 to 18 inches deep with the eye contact optics suspended over the desktop horizontally.